Abstract: A multi-stage automatic transmission using a reduction planetary gear and a planetary gear set in which the respective thrust forces generated thereat are supported by a low bearing load or a low case load. The automatic transmission is provided with a reduction planetary gear, coupled to an input shaft to fix a reaction force element so as to output a reduction rotation to an output element, and a planetary gear set, that outputs a speed shift rotation upon input of the subsequent reduction rotation. During at least first gear driving, there is provided a force transmission route in which thrust forces generated at one element of the reduction planetary gear and one element of the planetary gear set, respectively, are transmitted. In that route, a torsion direction of the helical teeth of the respective elements are set such that a direction of a thrust force of the element and a direction of the thrust force of the other element are different from each other during first gear driving.

Abstract: A gear supporting structure is designed to support two gears on a shaft with a short axial supporting span and without eccentricity or inclination. In this gear supporting structure wherein a first gear and a second gear are supported by a shaft in whirl-stopping and centering manners, the first gear with an axially extending boss portion is engaged with the shaft and fitted thereto in a centering manner at a whirl-stop portion and a first fitting portion, which are formed at different positions. A second fitting portion of the second gear is fitted to an outer periphery of the boss portion in a centering manner and connected with the first gear in a surface-fitting manner by a fastening device.

Abstract: In a method for performing a finish machining on a tooth surface of a gear to be machined, in the state that at least one counter gear 2 is meshed with the gear 1 to be machined, both gears are rotated while supplying water or an aqueous solution 4 which contains no abrasive grains to meshing portions of both gears so that a surface having a small surface roughness is formed on the tooth surface of the gear 1 to be machined.

Abstract: To reduce the axial dimension and size of a drive train for a hybrid vehicle, a rotor is supported within a recess formed in the end face of the a crankshaft and is further supported by the front cover of the torque converter. As a result, compared with drive trains which have a fixed member extending from the motor housing to support the rotor, the axial dimension and size of the drive train are reduced.

Abstract: A hydraulic control system includes switching mechanisms for receiving as a signal pressure a hydraulic pressure which is output from each shifting mechanism when all units of the shifting mechanisms are caused to output a hydraulic pressure, and being responsive to the reception of the signal pressure to be switched to a predetermined state for blocking a hydraulic-pressure supply path to specific hydraulic servos, thereby achieving a specific speed out of a plurality of speeds; and supply switching mechanisms provided in a hydraulic-pressure supply path to a hydraulic servo which is not included in the specific hydraulic servos, for switching between supply and cut-off of the hydraulic pressure to the hydraulic servo so as to assure two speeds in the event of the signal failure in a hydraulic control system for individually controlling engaging elements in an automatic transmission by using electric signals.

Abstract: A structure in which a hydraulic-pressure control applied pressure for controlling each engagement element of an automatic transmission is realized by using an electric signal such that combinations of engagement which encounter a tie-up in case of a failure of the signal lead to interlocking are inhibited to prevent deterioration in the durability of each engagement element. An automatic transmission incorporates a planetary gear transmission mechanism using selective engagement of at least five engagement elements to realize six gear ratios, and a hydraulic-pressure control apparatus for controlling the engagement elements of the transmission mechanism. Valves are provided which inhibit combinations of engagement of two or more engagement elements of the five engagement elements for interlocking the transmission mechanism.

Abstract: The automatic transmission of the present invention prevents fluctuation of torque transmission through a band brake. In the hydraulic operator for the band brake, a resilient elastic cushion is provided between a rod abutting one end of the band of the band brake and a piston. Any slippage between the band and drum of the band brake will result in oscillation of the rod. However, the elastic cushion absorbs oscillation of the rod, thereby isolating the piston from that oscillation.

Abstract: An automatic transmission disposed in a case with a speed change mechanism disposed around an input shaft, a gear supported to a support wall of the case so as to transmit the output of the speed change mechanism to another shaft extending along the input shaft, and a rear cover portion integrated with the case, thereby eliminating a joint portion with the support wall supporting the gear removably attachable to the case through an opening portion.

Abstract: A multi-stage automatic transmission using a reduction planetary gear and a planetary gear set in which the respective thrust forces generated thereat are supported by a low bearing load or a low case load. The automatic transmission is provided with a reduction planetary gear, coupled to an input shaft to fix a reaction force element so as to output a reduction rotation to an output element, and a planetary gear set, that outputs a speed shift rotation upon input of the subsequent reduction rotation. During at least first gear driving, there is provided a force transmission route in which thrust forces generated at one element of the reduction planetary gear and one element of the planetary gear set, respectively, are transmitted. In that route, a torsion direction of the helical teeth of the respective elements are set such that a direction of a thrust force of the element and a direction of the thrust force of the other element are different from each other during first gear driving.

Abstract: A multi-stage automatic transmission using a reduction planetary gear and a planetary gear set in which the respective thrust forces generated thereat are supported by a low bearing load or a low case load. The automatic transmission is provided with a reduction planetary gear, coupled to an input shaft to fix a reaction force element so as to output a reduction rotation to an output element, and a planetary gear set, that outputs a speed shift rotation upon input of the subsequent reduction rotation. During at least first gear driving, there is provided a force transmission route in which thrust forces generated at one element of the reduction planetary gear and one element of the planetary gear set, respectively, are transmitted. In that route, a torsion direction of the spiral teeth of the respective elements are set such that a direction of a thrust force of the element and a direction of the thrust force of the other element are different from each other during first gear driving.

Abstract: A gear supporting structure is designed to support two gears on a shaft with a short axial supporting span and without eccentricity or inclination. In this gear supporting structure wherein a first gear and a second gear are supported by a shaft in whirl-stopping and centering manners, the first gear with an axially extending boss portion is engaged with the shaft and fitted thereto in a centering manner at a whirl-stop portion and a first fitting portion, which are formed at different positions. A second fitting portion of the second gear is fitted to an outer periphery of the boss portion in a centering manner and connected with the first gear in a surface-fitting manner by a fastening device.

Abstract: A hydraulic control system includes switching mechanisms for receiving as a signal pressure a hydraulic pressure which is output from each shifting mechanism when all units of the shifting mechanisms are caused to output a hydraulic pressure, and being responsive to the reception of the signal pressure to be switched to a predetermined state for blocking a hydraulic-pressure supply path to specific hydraulic servos, thereby achieving a specific speed out of a plurality of speeds; and supply switching mechanisms provided in a hydraulic-pressure supply path to a hydraulic servo which is not included in the specific hydraulic servos, for switching between supply and cut-off of the hydraulic pressure to the hydraulic servo so as to assure two speeds in the event of the signal failure in a hydraulic control system for individually controlling engaging elements in an automatic transmission by using electric signals.

Abstract: A hydraulic control system includes switching mechanisms for receiving as a signal voltage a hydraulic pressure which is output from each shifting mechanism when all units of the shifting mechanisms are caused to output a hydraulic pressure, and being responsive to the reception of the signal pressure to be switched to a predetermined state for blocking a hydraulic-pressure supply path to specific hydraulic servos, thereby achieving a specific speed out of a plurality of speeds; and supply switching mechanisms provided in a hydraulic-pressure supply path to a hydraulic servo which is not included in the specific hydraulic servos, for switching between supply and cut-off of the hydraulic pressure to the hydraulic servo so as to assure two speeds in the event of the signal failure in a hydraulic control system for individually controlling engaging elements in an automatic transmission by using electric signals.

Abstract: In a state a vehicle is stopped at an intersection, an infinitely variable transmission is in a neutral position, a motor/generator rotates with a low speed, an oil pump and an auxiliary equipment are in rotating state. At that time, an input clutch is disengaged, and the internal engine is stopped. When the vehicle is started, a continuously variable transmission performs continuous shift control from the neutral position using hydraulic pressure from an oil pump, and the rotation of the motor/generator is transmitted to drive wheels via a ring gear of a planetary gear. After the vehicle has started driving, the input clutch is engaged and the internal engine is started. The vehicle is driven while the motor/generator assists driving or the motor/generator charges batteries based on operation of the internal engine.

Abstract: A hydraulic servo includes a cylinder, a piston and a rod. The piston divides the interior space of the cylinder between a closed hydraulic chamber and a back chamber which has an opening to the interior space of an automatic transmission. The rod is slidably mounted in the piston for relative movement through a predetermined distance. A frictional engagement element is engaged by the rod which is extended from one end of the cylinder by applying a hydraulic pressure to the hydraulic chamber. A passage is provided between the piston and the rod which is opened or closed by the relative movement between the piston and rod so that the hydraulic chamber and the back chamber are connected or disconnected. A valving arrangement (“closer”) closes the passage at the end of the return stroke of the piston toward the hydraulic chamber.

Abstract: A reduction in the weight and size of a speed-change mechanism is obtained by shortening a high-torque transmission system. The speed-change shock is attenuated by reducing an inertia torque in a muilti-stage vehicular automatic transmission. The vehicular automatic transmission is equipped with a planetary gear set that receives a decelerated rotation and a non-decelerated rotation as inputs and outputs a plurality of speed-change rotations, a reduction planetary gear, an input shaft that passes through an inner side of the planetary gear set, first and third clutches that couple the input shaft to two different speed-change elements of the planetary gear set respectively through the reduction planetary gear in an engageable and disengageable manner, and a second clutch that couples the input shaft to the other speed-change element of the planetary gear set in an engageable and disengageable manner.

Abstract: In a neutral N control for substantially equalizing axial forces to act on two pulleys, a belt type continuously variable transmission (CVT) self-converges into the gear neutral point (GN) at which the output shaft RPM takes the value 0. When the convergence is made to the GN point to establish a no-load state, the CVT establishes a force F.sub.A to converge into a pulley ratio of 1.0, in which it is stabilized by itself. A converging force F.sub.N to the GN point and the force F.sub.A toward the pulley ratio of 1.0 are repeated in a vortex shape in the load state and in the no-load state to establish a creep force. This creep force can be modified by generating a force F.sub.O against the force F.sub.A.

Abstract: A control system for an automatic transmission includes a fluid transmission unit connected to an engine; a clutch; a hydraulic servo; output RPM detector for detecting the output RPM of the fluid transmission unit; oil pressure generator for generating the oil pressure fed to the hydraulic servo; and a control unit. The control unit includes a booster for raising the oil pressure according to preset characteristics; change rate detector for detecting the RPM change rate of the output RPM in a preset range at the application of the clutch; and a corrector for correcting the preset characteristics by comparing the detected RPM change rate and a reference RPM change rate. The change rate detector detects the RPM change rate only when the output RPM at the time of starting the engagement of the clutch is higher by a preset value than the maximum of the output RPM in the preset range.

Abstract: An automatic transmission comprises a reduction planetary gear, two clutches transmitting a decelerated rotation transmitted from the reduction planetary gear, and a planetary gear set comprising two elements to which the decelerated rotation is inputted through the two clutches. The reduction planetary gear and the two clutches are arranged in one side of the planetary gear set. The second clutch is closer to the planetary gear set than the clutch. The input side member of the first clutch is connected to an output element of the reduction planetary gear and the input side member of the second clutch. The output side member of the first clutch is extended through the radial inner space of the second clutch and connected to one of the two elements of the planetary gear set. Thus, no member is arranged in the radial outer side of the both clutches, and the both clutches are radially enlarged.

Abstract: An automatic transmission, which establishes automatic shifts in a multiple gear stages by selectively inputting a plurality of input rotations to a planetary gear set, includes first and third clutches connected through a reduction planetary gear to an input shaft and transmits a decelerated rotation to the planetary gear set and a second clutch directly connected to the input shaft and transmits a non-decelerated rotation to the planetary gear set. The reduction planetary gear is arranged on the end of a boss portion of a transmission case wall and the one element is fixed to the end of the boss portion, hydraulic servos of the first and third clutches are arranged on the boss portion, a hydraulic servo of a second clutch is arranged in the other side of the reduction planetary gear from the hydraulic servos, and the hydraulic paths for the hydraulic servos are formed in the boss portion.